i rode like this for 2 months... take off the small chain ring if possible...
chances are the big ring will line up pretty close to the second or third smallest cog in the rear. MAKE SURE TO USE THE SAME CHAIN AS BEFORE (or the same diameter chain). shorten the chain to the right length, and ditch all the derailleur crap. You'll look like a bit of a tarck star... but it'll work.